Watershed Deforestation and Down-Estuary Transformations Alter Sources, Transport, and Export of Suspended Particles in Panamanian Mangrove Estuaries

We identified eight Panamanian watersheds in which conversion from wet tropical forest to pastures differed and assessed the effects of degree of deforestation, and down-estuary transformations, on the suspended particulate matter discharged from the watersheds, entering, traversing through mangrove estuaries, and emerging into coastal waters. Deforested watersheds discharged larger concentrations of suspended particulate matter, with lower % C and N, higher mineral content, and heavier isotopic signatures into fresh reaches of estuaries. Down-estuary, sediment entrainment increased non-organic content of particulates, and watershed-derived imprints of deforestation on composition of particulate matter were mostly erased by within-estuary transformations. Isotopic signatures of C, N, and S in particulate matter demonstrated strong land-sea couplings, and indicated that the direction of the coupling was asymmetrical, with terrestrial and estuarine sources delivering particulate materials to coastal waters and sediments. Mangrove estuaries therefore both act as powerful modulators of human activities on land, while also exporting particulate materials to sea.Fil: Valiela, Ivan. Marine Biological Laboratory; Estados UnidosFil: Bartholomew, Megan. Marine Biological Laboratory; Estados UnidosFil: Giblin, A.. Marine Biological Laboratory; Estados UnidosFil: Tucker, J.. Marine Biological Laboratory; Estados UnidosFil: Harris, C.. Marine Biological Laboratory; Estados UnidosFil: Martinetto, Paulina Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Otter, M.. Marine Biological Laboratory; Estados UnidosFil: Camilli, L.. Woods Hole Oceanographic Institution; Estados UnidosFil: Stone, T.. Woods Hole Research Center; Estados Unido